Hypodermic syringe.



T. M. QUARLES. HYPODERMIC SYRINGE. APPLICATION FILED JUNE 16, 1908.

Patented May 18, 1909.

Eli wanton wi iuuou .UNITEI) srrnr rs PATENT 0mm j r THOMAS M. QUARILES, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNQR OF ONE-HALF T0 DAVID B, CHAMBERLAIN, or

WASHINGTON, DISTRICT OF COLUMBIA.

HYPODERMIC SYRINGE.

To'all whom it may concern: I Be itknown that I, THOMAS M. QUARLES, of Washington, in the, District .of Columbia, have invented a certain new and useful Imrovement inHypodermic Syringes, and do iiereby declare that the following is a full,

clear, and exact description thereof, reference bein had to the accompanying drawings,'in which- Figure 1 is a perspective view of a hypodermic syringe embodying my invention;

. and Fig. 2 a longitudinal section thereof, the

arts being shown in full lines ready for unlatching for the automatic insertion of the needle, and in dotted lines in the position occupied after the automatic insertion.

The object of-my invention is to provide a hypodermic syringe possessing the excellences-of the syringe of United States patent to A. Dunbar No. 361,750, dated April 26,

1887, and certain important improvements a which experience in the manufacture and sale of the syringe of that patenthas shown to be necessary, that patent having been assi ned to me, and syringes thereunder havin een placed upon the market by me.

n. the embodiment of my inventionillustratedin the drawing, I employ a syringe barrel 10 and a piston 11, preferably of metal, at one end of a piston rod 12, having graduations as is common, to denote the amount of fluid to be injected, which graduations are cut or marked on a flat surface on the piston rod for the more convenient reading thereof, and also as is common, the piston rod is threaded for a nut 13 that constitutes a stop to lpositively restrict the expelling movement 0 the piston at the oint when the desired amount of fluid has een injected. On its outer end, the piston rod has a cap or head 14, by which the piston may be manipulated to charge the barrel and to expel its contents. The barrel 10 consists of a simple tube having atone end a removable plug 15 that is threaded at one end to engage the thread in the barrel, and is threaded at the other end for attachment of the customary needle 16, and when the needle isremoved the application of the customary cap, and said plug of course is erforated longitudinally from end to end y a hole 17. Intermediate its ends, the plughas an annular flange or enlargement preferably of the same diameter as the external diameter of the barrel, and in said flange is an annular groove 18 Specification of Letters Patent.

Application filed June 16, 1908. Serial No.438,84 3.

' Patented May 18, 1909;

' whose purpose will hereinafter appear. The

obj eat of, the removable plug=is to give access to the piston so that it may beconveniently treated toclean it or render it antiseptic, and to lubricate it when necessary.

The syringe barrel 10 is slidablymounted a tubular shell or casing 19, which at its end nearer the piston rod head or ca has screwed upon it a cap or head 20 which is perforated for the passage of the piston rod,

and between said cap or head 20 and the syringe barrel is interposed a coil spring 24 which normally tends tomove the barrel longitudinally of its inclosing shell or casing in the direction toward the point of the needle, and preferably a disk or collar 22 is interposed between the end of the spring and the endof the barrel to a ord a bearing for the spring end. Movement of the barrel by the spring is limited by -a circumferential flange or enlargement 23 on the disk-engaged end of thebarrel, and a shoulder 24 on the interior of the tubular shell or casing.

The syringe barrel may be moved into I the tubular shell or casing against the'pressure of the spring, and it is so moved preliminary to the automatic useof the syringe, and it is latched or held in position ready for operation by a latch that consists of a spring arm 25 which is secured at one end to the outside shell or casing, and at its other end has a ring 26 that encircles the shell 0 casing,

and o osite the oint of its connect'on with.

PP F

the spring arm plays in a slot 27 that is cut through the Wa of the shell or casing, so that it may enter the circumferential groove or recess 18 in the flange of the plug 15 when said groove or recess by the inward movement of the syringe barrel alines with the slot in the tubular shell or casing 19. By a slight pressure of the thumb on the latch arm 25, the syringe barrel will be released and instantly the barrel will be projected outward by the action of the spring 21, and the needle thrust into the flesh with such quickness and steadiness as to be wholly painless to the subject. After'the insertion of the needle, the contents of the syringe are expelled and injected in the usual way by pressure of the thumb on the cap or head of the piston rod to move the piston through the barrel, and to afford a convenient bearing for the fingers in this operation, the casing head 20 is provided with diametrically opposite arms 28.

' signal advanta es. means a s1mpl1 edconstruction becauseno instrument consists 'simp or casing and the operating spring side the barrel,

2 5 operation of t with the barrel. I ment' to be easily, set for automatic operation by pulling upon iston redhead or cap, the

s rin is Wholly outside the s rin e barrel; l his lo y g cation of the s ring results in several n the first place, it

modification of the syringe proper is necessary so that, as Wlll e a parent, theentire y-of a syringe of ordinary construction and the inclosingl shell and atch.

Again, no movable body being present in the fluid-rece1v1ng portion of the syringe, as is the case in the Dunbar atent herein-' the entire. uid-containing ortion of the syrin e barrel is filled with uid, andnot, as is t e case with the instrument of the Dunbar patent,-tpartially with air and fluid, after the needle has been injected. Again, the spring being Wholly outit can be made considerably larger and stronger than is possible with the construction of he Dunbar patent instrument, it being possible to give the spring a strength ampl adequate for the 'proper e instrument at all times. Another im ortant feature of my instrument arises rom the fact of the direct connection of the needle with the syringe barrel, or a connection-by which the need e moves This enables the instrucomfortably and safely before referred to,

the iston rod head or cap, so that in the act of'c arging the syringe by gullin on the arre may be rawn into the shell or casing into latchengaging position. Any danger from scratching or cutting the hand of the operator by the point of the needle, which exists'when 40 the setting operation is effected by pushing u on the-needle end of the apparatus, is

barrel and a head t us wholly obviated. If for any'reason the injection ot'the needle automatically. should not be desired, my instrument can be used in the ordinary way by hand insertion of the needle.

As I, prefer to construct it, instrument is all metal, a thin that simp 'fies its construction and ren ers it practically indestructible.

Havin thus described my invention, ,whatIcaimis- 1. The combination of a s ringe comprising a needle-carrying barre and a piston movable'therein,, and a piston rod having a handle, a tubular shell or casing in whlehsaid barrel is slidablfi mounted, a spring within the tubular she or easing wholly outside of the fluid-containing. portion of. the

barrel and directly actin to move'the barrel, the piston being movab e by the piston rod independently of the spring and a latch to' hold the barrel from movement by the spring.

' The combination of a syrin e comprising a barrel having at one end a p ug threaded to engage the barrel and threaded to en'- gage the needle, and an annular enlargement having a circumferential notch or recess,

and a piston in said barrel having a head- 1 carrying piston roda tubular shell or casin inwhich said bar rel is slidably mounted having a latch toengage said circumfer-' and a spring within said shell ential recess, 7 or casing interposed between one end of'the I on said tubular shell or casing the piston being movable Jby the piston rod independently of the spring.

In testimony that I claim the foregoing I have hereunto set my hand.

f THOMAS M. uARLE's witnessesz.

Gms. J. WILLIAMSON, K. WILLIAMSON. 

